Hello everyone. I have started my background for my aquarium finally. After seeing so many online, I have decided to have a go at it. Looking for any helpful hints to help keep this thing from popping out of the tank. I have carved all of it out of insulation board from lowes. Glued some of it together with silicone I and some with liquid nails power grab. Hoping it wont make a difference. I plan on coating it with plenty of drylok. Of course adding different cement colors to it. And on the last coat I want to add some sand to it here and there for some texture. I will be using silicone, lots and lots of silicone to attach it to the tank. I just hope none of the cave rocks come undone. Any help or ideas will be greatly appreciated. Thanks for reading. BTW it is going in a 55 Gallon with angels, neons, a common pleco, albino longfin pleco, african butterflys, two corys, and a ghost knife. A lot of fish I know. I will be getting another tank soon so I can put some of these guys in when they get big.

Is it designed to go all the way to the top of the tank? if it is then that should help to keep it all sandwiched together where you shouldn't have to worry much about it. Only section which may be a little concern would be the arch on the far left maybe. Are you planning on siliconing the foot of the arch to the bottom of the tank, or what's the plans for holding that down?